Coal-washing and ore concentration.



T. M. CHANCE.

COAL WASHING AND ORE CONCENTRATION.

APPLICATION FILED 0CT.Z. i915.

fT. M. CHANCE.

com. wAsHmG AND ORE coNcENRATIoN;

APPLICATION FILED OCT. 2, I9|5 lSe v Patented May 1, 1917. 3SHEETS-SHEET 2..

v nmMo/r T. IVI. CHANCE.

COAL WASHING AND ORE CONCENTRATION.

1,2%;16 y APPLICATION FILED OCT. 2, 1915. Patented Maly 1.

3 SHEETS-SHEET 3.

Inowwom 9 M z.

- 1,224, ISS.

, terials of different specific gravity are sepa- THOMAS M. CHANCE, orPHILADELPHIA, PENNSYLVANIA.

COAL-WASHING ND ORE CONCENTRTION'.

e Specification of Letters Iatent.

Patented May I, 19V?. l

Application filed October 2, 1915. Serial No. 53,761.

To all whom t may concern? Be it known that I, THOMAS M. CHANCE, acitizen of the United States, residing at Philadelphia, in the county ofPhiladelphia and -State of Pennsylvania, have invented a certain new and4useful Improvement in Coal-VVashing and Ore Concentration, whereof thefollowing is a specification.

My invention relates to a method of washing coal and concentrating oresin which ma- In carrying out my method the apparatus used may be greatlyvaried and the accompanying drawings are merely representative of thegeneral association of elements necessary to the operation of saidmethod.

lIt is Well known that if a mixture of coal andslate be introduced intoa-saturated solution of zinc chloridthe coal will float to or near thesurface of -sa-idl solution and the slate will sink toy the bottom ofthe container. Processes involving' the use ofl such solutions of highspecific gravity have never proven of commercial value in the cleaningof coal, and their use has been restricted to the laboratorydetermination of the physical characteristics of various fuels'. Thegreat difliculty -hitherto encountered in the application of thisprinciple to the concentration of ores and washingof coal has been thatin all cases the fiuid usedwas a liquid solution of either greateconomic value, or else possessedjof characteristics deleterious to theresultant product. For it will be readily understood that a portion ofthe solution-Will be inevitably carried" over with the separatedmaterials, o'r occluded within the pores of the individual grains ofsaidimaterials, and While some of the solution so lost might berecovered, the cost of vsuch recoverywould in most cases preclude theuse of the method.

The characteristic of my invention is that 'be emplo 'tion of the fluidmass.

either mechanically lthe fluid mass, which 'I use as a vehicle of highspecific g-ravity\f;er 'the separation of materials of differentspecific gravity, is in no sense a solution of a solid, or salt, in aliquid, but is a true mechanical mixture of a comminuted solid with aliquid,^said mixture being caused to assume the characteristics andproperties of a liquid by agitation.-

To this end the receptacle or tank yin which said separation is to beeffected is provided. with means for keeping said fluid mass properlyagitated and is also provided with means for the removal of theseparated materials v from said fluid mass after separation has beenaccomplished. .The tank having been filled to the proper level with saidagitated fluid mass, the material to be separated is introduced intosaid mass and that portion of the material of greater specific gravitythan said mass immediately sinks to theA from the tank by the meansprovided to that lower portion of the mass and is `removed Y l end,while that portion of said material` of.

a vspecific gravity approximating, or less than, that of said fluid massrises to, and is removed from, the upperV portion of said mass. In theforegoing description the separation is secured. by reason ofgravitational attractiombu't it Will of course-be understood that themethod may be carried out under conditions in which the action ofcentrifugal force is substituted for that of gravity.

In the accompanying drawings I- have illustrated diagrammatically fivetypes of apparatus tocarry out my method. All of the drawings arevertical cross-sectional views. Figure I illustrates an apparatus inwhich agitation of the fluid mass is accomplished by mechanical means. 1Fig. II

shows an apparatus in which'agitationfis produced by the introductionohydraulic water. Figs. III and IV are vertical crosssectionsillustrating the-application ofthe method to jigs yof the types in`common use, and Fig. V is a similar cross-section jillu'stra-ting a'typeof apparatus in whichl air may yed 'as a meansfor effecting agita-Like numbers indicate like parts in the drawings.

In theA drawings, Fig. I, 1 indicates al water-tight tank adapted tofcontain thev 4-iuid mass, in which an agitator 2, cari'ied in vsuitablebearings, is driven by a pulley 3. The material to be separated is fedinto said tank 1 through-a feeding device 4.- An elevator 5 is providedfor removing the separated material of lower specific gravity from saidtank 1, said elevatorjdischarging said material over a dewatering screen6, and an elevator 7 is provided for removing the "v5 separated materialof higher specific gravity from said tank 1, said .elevator dischargingsaid material'over a dewatering screen' 8.

' Saidelevators 5 and 7 are preferably pro? vided with ldewateringbuckets or other means whereby a minimum amount, of said liuidmass isdelivered on Asaid screens 6 and 8 in discharging the separatedmaterials fromtank-1, and said screens 6 and 8 are provided withcollecting boots 9 and 10 'which are connected to tank 1, either by achute or through a pump,"for the return of that portion of said fluid.mass Vpassing through said screens 6v and 8. 11 is a spigot forflushing tank 1.

'Ihe operation of the method when using' this apparatus for the washingof coal is as follows:

Assuming the tank'l tov be partially Vfilled witha fluid massconsistingv of a *mixture l 2 gravity approximating 1.45 and slate ofabout 2.3 specific gravity 4be introduced through the feeding device 4into said fluid' mass, the slate will immediately sink to the vbottom oftank 1 and be lifted out of said tank through the elevator 7. The coalbeing of .less specific gravity than the fluid mass wlll rise to the`upper portionof said mass and-be removedtherefrom by elevator 40 5.4That portion of the iuidmass mechani7 'cally carried over by elevators5 and A is reclaimed f in passing over dewatering screens 6 and 8, withorvwithout the asp sistance of washwater, 'and falls "into the boots' 9and 10 from which it isremoved and returns to tank 1. In 4the operationof the apparatusthe mechanical losses ofthe fluid mass, that 1s, that.portion of said mass carried away bythe slateY andcoal, may be madeup'bythe addition-gto'tankl of water tight tank'adapted to' contain the fffluid vmass into which the material to be separated is fedthrough afeeding device 4'. An elevator 5', in this case a dewatering wheel, isprovided for removing the separated material of lower specific gravityfrom said tank 1', said elevator discharging said material o verdewatering screen 6', and an elevator 7 1s provided for removingtheseparated material of higher specific gravity from said -tank 1',this elevator discharging said material over dewateriug screen 8. As

before described, said elevators 5. and 7 are I and II, and the liquid,etc., elevated by any will always be greater than one and less thanpreferably built as dewatering elevators,

and the screens 6' and 8. are provided with collecting boots 9 and 10for the return of that portion of the fluid mass reclaimed by saidscreens. 11 is a spigot for iushing 70 the-lower part of compartment 12.12 is a diffusion compartment for causing' even flow l through saidfluid mass of lthe hydraulic water introduced through valve 13 and pipe14 for agitation, by means of baiiles 15. 75

The operation of the method when using this apparatus for the washing ofcoal is similar to that described for the apparatus shown in Fig. I,with the exception that agitation of the fluid mass is produced throughthe medium of a rising current of water introduced through hydraulicwater pipe 14, instead of by mechanical stirring device 2. .-Tendency'ofthe hydraulic water to boil or low -unequally through the fluid mass ishindered by the diffusion compartment 12. This compartment is filledwith baffles, shown in this case as a layer of stone 15 placed betweentwo sieves, and these baflies tend to promote'even upward iow 90andprevent local currents ofthe hydraulic water through theV fluid massabove. It will of course beunderstood that the hydraulic Water,introduced through pipe 14, may ltself be a portion of the fluid mass,that is, itmay consist of a mixture of sand and water, being used overand over again; or it may consist of clear water from an externalsupply.

All of the drawings show outlets O from ,the boots 9 and l10 for thedischarge of the liquid and comminuted solid matter removed from theseparated material by the screens 6 and 8, and these may be connected bypipes or conduits p', p, as shown by Figs.

type of elevator, or pump, as illustrated diagrammatically by thecentrifugal pump C shown by Fig. II, and discharged througln 't the pipeor conduit d, d, into the receptacle 1',"either directly, or through thefeed hopper 4y as shown.

The apparatus -operated as shown by Fig. II, will thus be using-the samemixture Y forming the fluid-mass over and over again', but as there willalways be some loss jof liquid and also of comminuted solid ma- Y-terial, which is carried awayadhering to the separated materials, itwill be understood 'that vlike quantities of water and commi.

12C l I nuted solid material will be added to the Huid mass contained inthe receptacle 1, (1', 1a or A1") to make up for such loss and tomaintain the quantity and the specific grav ity of the fluid-mass nearlyconstant, so that the specific gravity of the Huid-mass another of thematerials that .are to be separated.

Figs. HI and IV illustrate this method of separation by means ofapparatus similar to 13u loc standard forms of jigs, in which thematerial to be separated and the Huid mass are moved relatively one tothe other 4by motion fluid mass,

' 1 27v an elevator for .material` and 6b and 8b imparted by jigmechanism in common use. To make it clear that no jigging action isnecessary, I have shown the apparatus without the sieves which injigging are necessary for the support of the jig-bed, but it will ofcourse be understood that sieves for controlling the iow in the 'hutch'may bev used if desired as illustrated by Fig. II.

Fig. III shows a plunger jig of the xed sieve type, commonly known asthe Hartz jig from which the sieve has been removed. In this drawing 16is the receptacle for the 17 is a plunger operated by the eccentric 18,19 is la feed hopper for material to be separated and also for materialof which the fluid mass is composed, 20 is an overflow for separatedlight material and 21 is an elevator for removing separated heavymaterial, and 6a and 8fL are separating screens for removing theinsoluble comminuted material and liquid from the separated materials.

operated, 25 is the feed hopper, 26 is an overflow discharge forseparated light material,

removing separated heavy liquid from the separated materials. Fig. V

` isp-similar inmany `ratus shown by Fig. I as indicated by the yfixedin position `mg cross .piece .p

of itslparts to the appareference numbers referringto those parts, vbut1t 'is provided with a 3 andis free to rotate lin a'stuiing box 3l on aplatform or support- 32, andmay thus be supplled with air -underpressure through the 4pipe 33 from any source of supply of air underpressure. The hollow shaft 80 is Vconnected with hollow radial arms 34closed at the ends but provided with small perforations 35' for theescape of air as jets of small diameter. The operation of the methodwith this apparatus is similar to that of apparatus already described,the fluid mass being agitated by air.

While inthe foregoing description of the' operation of the method thefluid mass was described as being an agitated mixture' of sand andwater,'it will be understood that i any mixture of suitable consistencyof .a

comminuted solid and a liquid may be used,

t Fig. IV shows a movablev sieve jlg in which the apertures of the sieve`freely through them, thel drawing be attached, 24',

are screens for removhollow shaft 30 which maybe rotated by means of theplley provided the specific gravity of the resultgreater specificgravity than this material,

and these grains, which with the liquid used comprise the iuid mass,should not be widely separated. It may be composed of sand, crushedwaste, or other material of'v suitable properties. If the method be usedin the concentration of ores, finely comminuted middlings orconcentrates may be employed. Y

xIn the accompanying drawings the various adjunctive devices shown forthe operation ofthe method are intendedto represent the; generalassociation of elements necessary to such operation, but I do not limitmyself to the use of the forms shown. Asbefore stated, theapparatusnecessary to the operation of the method must always consist ofthe following elements: A kreceptacle adapted to contain a Huid mass,said mass consisting of anagitated mixture of comminuted solid matterand liquid, means for agitating said iuid'ma'ss', means for introducinsaid uid'mass, and means for the removal ofthe separated materials fromsaid fluid mass after separation has beenv accomplish ed. yIt will beunderstood that the receptacle `maybe of any desired shape orJ form .and

that one o r more such receptacles may be the .material to be separatedintov leo employed. The means shown in the drawings for the removal ofthe separated materials from 'the fluid mass are intended to be typicalof elevating devices. in common use,

as any other forms, such as belt conveyers,

etc., may be read-v scraper'lines, sand wheels, ily used. lIn certaincases the means employed to these ends may do away with such elevatingdevices entirely, the sepa-v rated material of lower specific gravitybeing floated out of the receptacle-as in some forms of jigs-and that ofhigher specific gravity being trapped out of the machine periodically,in the same manner that the Y slate is trapped out of the hutches ofcoal jlgs and washers. The feeding device may .be of any of the forms incommon use,

although feeders of the type in which the material is fed in a thinstream are preferable, and the feed may be introduced either above orbelow the surface of the fluid mass, and at either the center or theedge of the receptacle containing said mass. tation of the fluid 'massmay be mechanically shaking, apparatus, or by] the addition of hydraulicwater, with eit er a uniform or produced .The agiby any type ofstirring, orl

` pulsating flow. Similarly, air may be introducedinto the uid mass forthe purpose `of agitation as is commonly practised in cyanid agitationtangs, and this air may have either uniform or pulsating flow. In somecases 1t' may be desirable to produce the agitation of the fluid. massby causing said mass and the material that is to be separated to moverelatively to each o ther. Such lrelative movement may be accomplishedby using apparatus similar to the standard plunger jig with fixed sieve,the operation of which may 1n many cases be removed from said materiallby the use of wash water, or by passing the material over screens orthrough any of the stand-ard types of upward current hydraulicclassifiers. vThe comminuted solid -used for producing the fluid masswill generally be' so very much smaller than the material vseparatedthat it can be lifted Aby a current of water that will not disturb saidmaterial to any degree. Washing or classifying devices of this kind maybe conthe fluid mass be kept constant Within cer- -structed integrallywith the apparatus or may be separately used as auxiliaries.

It is desirable that the specific gravity ofv tain limits and to.accomplish this result the apparatus may be provided with means forincreasing or reducing the percentages of comminuted solid material andliquid vin said mass. It may in some cases be advisable Sto make such-means automatic, and this may be readily accomplished byv any oneskilled in the art bythe use .offloats of proper 'specific gravitylinked to the source of supply of either the liquid orthefcomminutedsolid or of both." A discharge weir inthe tank containing the liuidmassmay be usedy if desired, to keep said mass from rising above apredetermined height. lIt should be pointed out that while in someembodiments of apparatus .for carry- 'l ing Aout themethod a current ofhydraulic water, orl of an elastic fluid su'ch as air, is. used for theAagitation of the Huid mass; such v current is 'only strong venough to,secureV properagitation of the finely comminuted solid and is not inany case intended to produce a classifying or concentrating ac is to beseparated.

tion upon 'the relatively large'material that Asthe separation is(produced purelyv by flotation, the' relative size or shape "of thedifferent grams of the materialthat is to be separated wlll have littleor no' effect in `the separation; and the grouping of large grains oflight ymaterial with small grains of heavy material, by their fallingvelocity,- as in jigging or classifying,-is not made use of in any way.Hence one of the greatest difficulties that is ordinarily encountered incoal washing or ore-dressing-the mixing of thin, fiat grains of heavymaterial with grains of much lower falling velocity, due to the heavygrains' being. caught on their flat side by the separating current, andthe reverse case, in which flat light grains fall endwise through acurrent that shouldlift them-is eliminated. Anothergreat advantage ofthe method is that the materials after separation are in positionsrelatively remote from each other, therefore the difficulty ordinarilyencountered in securing `clean discharges from jigs, due to the closeand varying nline o f contact between the/refuse and the jidged product,is not metl with. The use of3 mixtures. of finely divided solids, suchas clays, with water, in upwardJ current classifiers is known. Suchmaterials when finely divided form suspensions in water that approachsolutions in their physical properties and hence it is exceedinglydiiiicult to separate the concentrate product from mixtures of thiskind. It will of course be understood that it is impossible to obtaincomminuted materials, eithernat ural sands or sands mechanicallyproduced, that will contain no trace of such finely divided material,and the expression mixture of appreciably coarse granular material asused in the claims hereof is intended to mearlmixtures of comminutedinsoluble material and liquid possessing physical characteristics thatinno sense'approach suspen- -sions or solutions, but that requirecontinuous' agitation to assume and preserve the fluidic properties.herein described and It, will of course be understood that apparatusemploying my method may be used in series, the products discharged fromthe first machines being re-treated on those succeeding, either forrecleaning or for further v VInaintaining by agitation a' uniformlydis-'.- tributed mixture of appreciably coarseI granular material andliquid, whereby a fluid'ma'ss'pf relativelyhigh specific gravityanduniform composition is formed; intro-- ducing said materials intosaid 'uid ma'S'S, permitting said materials to separatevinfsaid Huidmass and removing the Vresultant prod- 'uct vof said separationl fromsaid fluid mass,... 1302.2 l

2. A method of separating materials of different specific gravity whichconsists in maintaining by agitation a uniformly distributed mixture ofappreciably coarse granular material and liquid, whereby a Huid mass ofrelatively high specific gravity and uniform composition is formed;introducing said materials into said Huid mass; permitting the materialof relatively low specic gravity to rise to the upper portion lowerspecificl gravity than said mass to rise to the upper portion of saidfluid mass; and removing the materials, thus separated, from said fluidmass.

4. A method of washing coal which'consists .in feeding said coal into afluid mass of relatively high specific gravity,` maintaining said fluidmass by agitating a uniformly distributed mixture of appreciably coarsegranular material and liquid; permitting the `coal of relatively lowspecific gravity to rise to the upper portion of said fluid mass;permitting the impurities of relatively high specific gravity to sink tothe lower portion of said mass; and relmoving the coal and impurities,thus separated,pfrom said fluid mass.

.5.A method of washing coal which. consistsv in feeding said coal intoan agitated mixture ot sandV and water, composing a gravity n permittingthe coal of relatively low speclclgravity torlse tothe upper portion ofsaid {luid-mass; permitting the impurities of relatively high specicgravity to sink to the lower portion of said fluid mass; and removingtheI coal and impurities, thus separated, from said fluid mass.

6. An apparatus for the separation of ma- -terials of diili'erentspecific gravity comprising in combination, a receptacle adapted tocontain a fluid mass consisting of an agitated mixture of appreciablycoarse granular material and liquid; a Huid mass consisting of saidmixturein'said receptacle; means for maintaining by agitation the iuidicproperties of said tluid mass, whereby the separation is effected bydifferences in specific gravity and not by the classifying action of acurrent of liquid; means for introducing into said fluid' mass'thematerials to be separated and means for removing said materials, afterseparation has been v effected, fromsaid fluid mass.

7. An apparatus for the separation of materials off-different specificgravity comprising in combination, a receptacle adapted to means formaintaining by agitation the fluidic properties of said liuid mass,whereby the separation is ,e'ected by differences in Yspecific gravityandnot by the classifying action of a current of liquid; means for.introducing into. said fluid mass the inaterialsto be'separated; meansfor removing said materials, after separation has been-effected, fromsaid fluid mass and means for separating from said materials so removedportionsV of saidfluid mass adhering' THOMAS M. CHANCE.

Witnesses:

H. M. CHANGE, E. R. BARNABD.

